Firing mechanism



J. G. SEITZ FIRING MECHANISM Original Filed Nov. 28, 1939 INVENTOR. 15 1 6. 55/12 BY M MK,

Aug 13, 1946;;

Patented Aug. 13, 1946 FIRING MECHANISM John G. Seitz, San Francisco, Calif., assignor to Samuel I. Keene, San Francisco, Calif.

Original application November 28, 1939, Serial No. 306,481. 7 Divided and this application May 6, 1944, Serial No. 534,393

1 Claim.

This invention relates to improvements in the firing mechanism of firearms, and is a division of application, Serial No. 306,481, filed November 28, 1939, now Patent No. 2,350,833, dated June 6, 1944.

One of the objects of the invention is the provision of improved means for causing the actuation of the firing mechanism for firing the piece, and which piece may be in any one of the small arms, such as the pistol, revolver, rifle, or shotgun, wherein the firing of the piece is efiected through a finger operated trigger.

Another object of the invention is the provision of improved means associated with the finger actuated trigger of a firearm for indicating to the user the exact moment at which the firing mechanism will be actuated for firing the cartridge during a movement of the trigger in one direction and after a greater movement has taken place in such direction than in trigger mecha nisms of the so-called hair-trigger type.

A still further object of the invention is the provision of improved, safe means operatively associated with the finger actuated trigger of a firearm of the type in which the firing mechanism is actuated for firing the cartrid e during the release of the trigger under the influence of a spring but checked by the trigger finger of the operator for indicating to the user the exact moment at which an extremely slight further release of the trigger will effect a firing of the cartridge.

Other objects and advantages will appear in the specification and drawing annexed hereto.

In the drawing,

Fig. 1 is an enlarged fragmentary side view of a rifle at the breech, partially broken away and partially in section, showing an example of my invention in which the cooking piece is cocked but in which the trigger and firing mechanism is inoperative for firing the piece although the former may be retracted and fully released to travel through its full stroke.

Fig. 2 is a view similar to that of Fig. 1, but in which the firing mechanism is operative for firing the piece at a point during the release of the trigger after a full retraction thereof.

Fig. 3 is an enlarged fragmentary View of a portion of the firing mechanism that is particularly adapted to accomplish the objects of the invention.

In describing the particular type of firing mechanism herein, the term trigger release will be used, and which term designates the type in which the actuation of the firing mechanism or release of the cocking piece, occurs at a point during the release of the trigger after a retraction thereof. The compression type trigger mechanism is the opposite type in which the re lease of the cocking piece occurs during retraction of the trigger. This latter type is the one most commonly used at the present time;

The advantages of a firing mechanism in which the firing is efiected by release of the trigger rather than during retraction thereof are many, among which are (1) elimination of nerve strain heretofore present where-sighting and positive pressure and tightening of the muscles are required simultaneously, (2) the elimination of relatively long and arduous training required by novices for gaining a relatively high degree of accuracy in shooting, (3) elimination of the tendency to draw the sighted firearm oif the target at the time of firing. All of the above eliminated disadvantages directly contribute to better and faster shooting. However where the trigger mechanism is of the trigger release type it is also desirous that the operator have an indication of the exact point during release of the trigger at which the firing mechanism will be actuated, and this actuation should not come at the moment when the fully retracted trigger starts its return movement under the power of the spring that is compressed during retraction. A slight amount of play or movement should first be permitted so that the operator will be relieved of any tenseness in holding the trigger retracted. If this movement were not permitted it would be likely that the operator would exert far more strength than would be necessary to safely hold the trigger in retracted position, and would develop an undesirable nervous tension through fear of accidental release and consequent firing of the piece.

The invention herein provides for a substantial and abrupt resistance to the release of the trigger under release of the pressure therein by the trigger finger. Upon encountering this resistance (when the release of the trigger is under control of the trigger finger during its release) the trigger movement will stop until a still further release of the pressure by the trigger finger permits it to move past said resistance. This further movement is very slight so that the trigger virtually becomes a hair trigger once the said resistance is encountered. It is to be noted that during all this release of the trigger the latter is being moved by the power stored in the spring during retraction of the trigger and the force applied to the trigger by the trigger finger is a progressively reduced force rather than a positive and progressively increasing force as is the case where the compression type trigger mechanism is employed.

In detail, the invention as illustrated in the drawing is applied to the conventional 1903 model Springfield rifle that is provided with a stock having a pistol grip I, cocking piece 2, trigger 3, bolt 4, and the usual barrel, etc. The cocking piece 2 is provided with the ordinary sear notch for engaging a sear nose 6 on a= sear l for holding the cooking piece 2 cooked or drawn back under the expansive force of the usual main spring (not shown). When the sear nose is withdrawn from engagement in the sear notch the cooking piece and conventional striker (not shown) are released to cause the striker or firing pin to strike the percussion cap of the cartridge. they, or their equivalents, are usually found in firearms.

"In the following description the terms forward, rear, and the like, are used withreference to the barrel. For example, the forward end or portion of an element is the end or portion nearest the barrel, and the f'rear end or portion of an element is the end or portion remote from the barrel, while the terms rearwardly and forwardly likewise are used with reference to the said barrel. All of the'elements hereinafter described are disposed rearwardly of the barrel and substantially below the bolt.

The sear nose 6 is rigid on sear 1, the latter being an elongated bar extending horizontally as seen in Figs. 1, 2 with the nose 6 positioned at a point intermediate its ends and projecting thereabove. Sear 1 is disposed below the firing pin and cocking piece, and in a chamber 8 that is rearwardly of the magazine 9. The rear wall it] of said magazine constitutes the forward wall of chamber 8. The forward end of sear 1 termi-. nates adjacent wall If] and spaced slightly from said forward end is an expansion coil spring I! that is adapted to react between the upper wall l2 of chamber 8 and said forward end of the sear. Sear pin [3 adjacent the forward end of said sear, and between spring I i and nose 6, pivotally supports said sear in said chamber for swinging about the horizontal axis of said pin. The spring ll yieldably urges the rear end of the sear including the nose 5, in an upward direction for holding the nose 6 in a position in engagement with the sear notch 5. Upon urging said rear end of the sear downwardly the nose 6 will be released from engagement with the notch 5 and the firing pin will be actuated under the influence of the main firing pin spring (not shown) for firing.

The upper end of trigger 3 extends into said chamber 8 and past the sear 1 for pivotal movementof the trigger on pivot pin I4, the latter beingsecured. to the walls. of chamber 8 above. the sear, said .sear being notched on its upper side to pass the said pivot pin. Adjacent pin 14. the upper end of said trigger is formed with a rearwardly projecting enlarged portion i=5. Be.- tween said portion 14' and wall I2: is an expansion coil spring it that yieldably urges the lower end of trigger 3 forwardly for holding the same in a forwardly urged position unless and until the sameis retracted or is. moved rearwardly by the trigger finger of the operator. Upon such retraction of the trigger the spring H5 is compressed and its expansive force is what causes a release of nose 6 from the sear notch, 5 asthe retractive The foregoing elements are old and 4 force of the trigger finger is relieved, as will later be explained more in detail.

The lower end of trigger 3 extends downwardly into the area enclosed by the guard bow H, as is conventional in most firearms.

Below the sear l is a horizontally elongated bar l8 that is pivoted at its forward end to trigger 3 by a horizontal pivot 19. The upper side of said bar is formed with an upwardly opening recess extending longitudinally of the bar, in which recess is an elongated element 20 secured to said bar at its forward end by a pivot 2|. The rear end of said element is formed with an upwardly extending projection 22 that provides a forwardly facing shoulder 23 or notch at the forward side of said projection. The rear end of said element is yieldably supported in a position slightly elevated above bar [8 on a spring 24 that is disposed between said element and the bottom of the recess in which said element is positioned (Fig-3).

Bar 18 is movable with trigger 3. Thus upon 7 retracting the trigger the bar l8 carrying element 20 will move rearwardly and the bar and element will be carried forwardly by the trigger when the latter'i's released. Spring I6 will effect such forward movement.

The lower side 25 of chamber 8 carries the guard bow i1, said side being commonly called a guard plate. Said plate extends rearwardly of the guard bow at 26, and rear guard screw 21 secures said extension 26 to the stock in the usual manner.

At about the juncture of the rear side'of guard bow I! with extension 26, the guard plate is formed with slot 28. Said slot opens downwardly' and outwardly at about the said juncture and terminates at its upper open end at a point below the rear end of bar l8 when the trigger is in normal forward position.

Just rearwardly of the rear end of bar l8, and also rearwardly of the upper end of slot 28, the plate 25 is formed with an opening for a vertical pin'29 to pass therethrough. The lower end of said opening opens into the slot'28 near the lower end of the latter, the said slot extending slantingly upwardly and forwardly from its lower end.

On the upper end of pin 29' is a block- 30 that is adapted to seat in an upwardly opening recess 3!. The'recess 3| is formed in an enlargement 32 projecting from the guard plate into chamber 8. This enlargement is at about the juncture between extension 26 and said guard plate. The forward wall of recess 3| is slanted upwardly and rearwardly from the forwardly facing side of said wall, and the forward edge of block 30'is about even with the upper edge of said forward wall. A groove 33 (Fig. 3) extends across the upper side of block 36'' transversely of the longitudinal axis of the firearm and the upper side of block 30 rearwardly of the groove 33 is substantially higher than the portion of the block forwardly of said" groove. This latter portion of block' 3'6 has its upper surface extending slantingly in continuation of the slanted upper surface of the forward wall of the recess in which the blockseats (Fig. 1);

The rear end of bar I8 is slanted on its under side to generally correspond with the slant of the forward wall of recess 3| so that upon' re-- traction of trigger 3 the said correspondingly slanted surfaces of bar It and block 30 will be in slidable engagement and the rear end of bar l8 will be caused to move upwardly (Fig. 3').

It will be seen (Fig. 1) that when block 30 is seated in recess 3| the rear end of bar l8, including element 22, will be elevated a predetermined distance upon full retraction of trigger 3. The dotted line position indicated in Fig. 1 shows the trigger 3 retracted its full distance, and bar l8 and element 22 are elevated. It is also seen in Fig. 1 that oscillatory movement of the trigger through its full stroke will not cause a release of sear nose I 6 from the sear notch since the bar I8 is not sufiiciently elevated.

The release of the sear nose 6 upon forward movement of trigger 3 is effected through actuation of a cam member 34 that is pivoted at 35 to the rear end of sear 1 rearwardly of nose 6. Cam member 34 is formed with a downwardly extending projection 36 that terminates at its lower end at a point spaced above the rear end of bar [8 when the latter is in its forward position. The cam member 34 is formed with a portion at its upper end extending upwardly and forwardly of pivot 35 and in engagement with the upper wall I2 of chamber 8. This engagement between said portion of the cam and wall I2 is maintained at all times by action of spring II. A stop 31 on said cam below pivot 35 engages the rear end of scar 1 to prevent rearward movement of said projection 36 beyond a predetermined point while permitting forward movement thereof un-der force.

Referring to Fig. 2, it will be seen that when the block 30 is elevated and is held elevated a retraction of trigger 3 will cause the rear end of bar 18 and element 29 to be elevated or raised to a position where projection 22 on element 20 will slidably engage the lower end of projection 36 on cam member 34, thus depressing the rear end of element 20 against spring 24 until projection 22 passes rearwardly of the lower end of projection 36. Thereafter upon release of the trigger 3 and forward movement of bar l8 and element 26, the shoulder 23 on said element will engage the lower rear corner of projection 36 and will move the projection forwardly thereby causing the upper forward portion of the cam to move upwardly. This upward movement of said portion of the cam forces the rear end of sear 1 downwardly about pivot l3 thereby releasing the nose 6 from engagement with notch and thus causing actuation of the firing pin for firing.

The elevating of block 3!! is effected by an arm 38, one end of which is pivoted at 39 in the guard plate at a point forwardly of pin 29. This arm 38 extends rearwardly and downwardly in slot 28 below pin 29 and terminates in a plate 40 rearwardly of the guard bow and below pistol grip I of the stock. This plate 40 is relatively wide and is adapted to be comfortably gripped by the several fingers of the hand that embraces the pistol grip during shooting or during carrying of the firearm in ready position, or across the body. In other words, at any time that the rifle or firearm is carried in, or is moved to a position from which it may be fired, the plate 40 is adapted to be gripped by the fingers of the hand that carries the trigger finger. This plate 40 thus functions as a safety device inasmuch as the release thereof by the fingers gripping it will permit said arm to fall away from the stock to the full line position of Fig. 1 inwhich position any actuation of the trigger will be inoperative for releasing the cocking piece.

In operation the stock of the rifle or firearm is gripped by the hand adjacent the trigger guard bow and the trigger is fully retracted to the dotted line position in Fig. 2. A preliminary sighting may be taken during which operation the operator may release the pressure on the trigger suificiently to permit the bar [8 and element 20 (Fig. 3) to move forwardly until the shoulder or notch 50 in the inclined underside of the rear end of bar I8 engages th forward upper edge of block 30. At thi point the forwardly facin shoulder 23 on element 20 engages with the projection 36 of cam member 34 and an abrupt increased resistance will occur due to the straight ahead motion of member 20 against the resistance of projection 36, and a very slight further forward movement of the member 20 would actuate the cam member 34 for releasing the nose 6 from notch 5 of the cooking piece. At this point'the operator takes final aim and then again releases the pressure on the trigger to permit the release of the cooking piece.

The inclined surfaces at opposite sides of notch 50 (Fig. 3), particularly ahead of said notch, enables the desired forward movement of the bar l8 and member 20 with relatively little release in pressure against the trigger even though the forwardly facin shoulder 23 of member 2|] were to be in engagement with the projection 36 slightly before notch 56 engages member 30 inasmuch,

as there would be a, sliding movement of said shoulder relative to projection 36 until the notch 50 engages the forward upper edge of member 30. Such slow movement of projection 36 that would occur were the shoulder 23 in engagement therewith before notch 50 reached block 30 would become fast after the notch 50 reaches block 30, which would result in a fast release of the cocking piece upon release of the trigger after notch 58 has reached block 30.

The result of the above structure is that the operator is relieved of any nervous tension he would otherwise be under were the firing to be effected immediately upon a release of the retracted trigger, or at a time not determinable by feel on the trigger. Also the fact that the release of the cooking piece is effected by the force of the spring l6 as controlled by the trigger finger instead of being effected solely by the force of the trigger finger, enables the structure, here comprising notch 50 and block 36, to provide a far more effective indicating means than would be the case in trigger mechanisms of the compression type. In the releasing trigger mechanism the muscular tension applied to controlling the release of the trigger is concerned purely with the relatively light force of spring I6 that returns the trigger to its forward position and the relaxing of muscular tension is accomplished with far greater steadiness and precision than is possible in increasing physical tension, as occurs in the compression type trigger. This fact makes it apparent that the combination of structure providing for an abrupt increased resistance in a trigger of the releasing type enables the accomplishment of results not possible in a trigger of the compression type.

In the event the trigger of applicant's firearm is retracted and the operator does not wish to fire the piece, the mere release of the fingers gripping plate 46 so as to permit the dropping of said plate, will result in lowering block 36 away from bar "3 and then the trigger may be released without releasing the cooking piece.

Having described the invention, I claim:

In a firing mechanism for firearms that includes a cocking piece and holding means therefor for holding it cocked and movable in one direc- 8 ment or :said trigger past said point; said cocking p'iece being released :at said point, said last mentioned means including a notched element :connected with said trigger :for movement therewith, and a member in slidable engagement with said element during said return movement of said trigger and prior to release of said cocking piece and having a shoulder engageable in the notch in said element immediately prior to said :10 movement past said point.

JOHN G. SEITZ. 

